Comparative energy assessment of three glazed courtyard roof designs in a cold climate heritage building

Abstract

The use of translucent roofs over courtyards in historic buildings has become a common strategy in rehabilitation projects. However, many of these interventions are carried out without bioclimatic or energy-efficiency criteria, leading to risks of overheating and thermal discomfort, particularly during summer. This issue is expected to worsen with climate change, compromising the habitability of these spaces. This study compares the thermal and energy performance of three glazed roof configurations: a triangulated dome, a flat roof, and a south-facing sawtooth roof with vertical glazing. The case study is a Renaissance courtyard located in Burgos, Spain (continental Mediterranean climate). Dynamic simulations using EnergyPlus and Ecotect evaluate solar exposure, annual heating and cooling demand, free-running thermal behavior, and daylight availability. Results show that roof geometry has a decisive impact on energy efficiency. The sawtooth solution eliminates cooling demand under passive operation and maintains thermal comfort (20–25 °C) throughout the year while ensuring daylight levels above 4000 lx. These findings support the use of passive geometric strategies to improve climate adaptation in enclosed heritage courtyards. The methodology is replicable in similar cold-climate contexts and offers practical guidance for energy-efficient retrofitting of historic buildings.